This invention relates generally to a method of and surgical apparatus for use in preparing a bone cavity for subsequent implantation of a joint replacement prosthesis. The invention has particular application to a surgical reamer for enlarging and shaping a cavity within a femur for the implantation of the femoral component of a hip joint prosthesis.
A natural hip joint may undergo degenerative changes due to a variety of etiologies. When these changes become so far advanced and irreversible, it may become necessary to replace the natural hip joint with a prosthetic hip. When implantation of such a hip prosthesis becomes necessary, the head of the natural femur is resected and a cavity is created within the intramedullary canal of the host femur for accepting and supporting the prosthetic hip.
Conventionally, the cavity within the intramedullary canal is formed in part by using a series of rasps, each of which comprises a handle and a serrated shank joined to the handle. To form the cavity, each of the rasps are in turn moved sequentially into and out of the cavity in generally a straight line. However, such a movement may not produce the ideal cutting action when the surface to be formed is curved to follow the medial cortex, and sometimes the anterior, posterior and lateral cortices. Reamers have also been used to form cavities in the intramedullary canal prior to the implantation of a hip joint prosthetic device. However, such reamers were generally inflexible and therefore do not precisely follow the shape of the cortical bone.